Means for heating compressed gas.



PATENTED NOV. 6, 1906.

W. H. SODEAU. MEANS FOR HEATING COMPRESSED GAS.

APPLIOATIOK FILED AUG. 21. 1906.

WzZizwm 7Q fzwerzzoz w 35 mm ITED STATES PATENT OFFICE.

WILLIAM HORACE SODEAU. OF NEWCASTLE-UPON-TYNE, ENGLAND, ASSIGNOR TO SIRW. G. ARMSTRONG, WHITWORTH & COMPANY LIMITED, OF NEWOASTLE-UPON-TYNE,ENGLAND.

MEANS FOR HEATING COMPRESSED GAS- Specification of Letters Patent.

Patented Nov. 6, 1906.

Application fil d August 21,1906. Serial No. 276.029.

. DEAU, eng'neering chemist, a subject of the of r Kin eat Britain,residin' at Elswick Wor s, Newcastle-upon-Tyne, ngland, have inventedcertain new and useful Improvements in Means for Heating Compressed Gas,

-of which the following is a specification.

It has before been proposed to heat compressed air or gas by means ofthe combustion in it of petroleum, alcohol, or other suitablecombustible liquid, thereby raising the temperature of the air andconsequently increasing the volume which a given weight would occupy ata given pressure. The rise of temperature has other beneficial effects,notably that it is capable of preventing the formation of ice from anwater which may have been carried forwar by the compressed air.

According to this invention the-combustion takes lace inside the pipe orpassage through WhlGh the compressed air is supplied to the engine orpneumatic tool, whic pipe or (passage will usually be locally increased1n ameterin order to provide a combustion chamber of sufficient capacityand suitable sha e, and the arrangement is such that the ratio of fuelto air can be kept practically constant or can be varied at pleasure.

The combustible liquid is contained in an appropriate vessel orfuel-reservoir communicatin with the compressed-air-supply pipe at apoint where the pressure is higher than in the combustion-chamber andconnected to a pi e passing into the combustion-chamber, w ere itpreferably terminates in a suitable spraying-nozzle.

In some installations there may be an already existing drop of pressurewhich can be utilized for feeding the combustible liquid into thecombustion-chamber; but it is usually necessary to interpose a specialobstacle, such as a cock or a perforated plate, in the path of thecompressed air.

The amount of combustible liquid fed into the combustion-chamber per umtweight of compressed air will of course depend upon the relativedensities of the two fluids and the relative resistances in the paths ofeach. Thus the relative proportion of a given combustible liquid may beincreased by decreasing the size of the hole or holes in the perforatedplate above described or by increasing the orifice through which thecombustible liquid is discharged. The same effect is produced bydecreasing the pressure, and consequently the density, of thecompressed-air supply; but if the mean pressure 1s kept constant theproportion will be but little influenced by the rate at which thecompressed air is passing, as the stream of combustible liquid will varyin racticall the same de gree. It will thus e seen t at withinreasonable limits any desired temperature can be obtained by alteringthe mean pressure or by changing the arrangement producing the dro inthe air-pressure or by changing the fue -delivery orifice.

When only a moderate rise of temperature is desired, as in the case ofpneumatic handtools, 800., only a portion of the total air-supply needbe sent through the combustionchamber, ap ropriate cocks, valves, orother controllin evices being employed to obtain the desire ratiobetween the two air-streams which streams are, of course, subsequentlyreunited.

In installations which are required to run for long periods I preferablemploy two or more fuel-reservoirs provi ed with appro priate cocks orvalves so arranged that an empty reservoir may be shut off and refilledwithout interfering with the continuous ac tion of the appliance. Thespraymay be ignited by introducing a piece of burning material into thecombustion-chamber after temporarily relieving the pressure in the same(appropriate valves, cocks, doors, 800., being provided for this p ose)or while the compressed air is actual y traversing thecombustion-chamber by means of an igmtiontube, primer, cap, or electricignition device.

Figure 1 is a diagrammatic sectional elevation of an apparatus suitablefor use with pneumatic hand-drills and the like. Fi 2 is is a milar viewof an apparatus suitab e for tor edo propulsion.

n Fig. 1 the greater part of the air passes through the cook a in themain supply-pipe b, by which it is ,led to the engine; but a portiontakes the alternative path through the pipe 0, which forms a connectionbetween the airsupply pipe I) and the combustion-chamber e,

plpes and becomes heated and then rejoins the main streamthrough thepipe f and cock 9.

Li uid fuel'is contained in the fuel-reservoirs 7', which are connectedto the air supply pipe. b. by the pipes c c and Z and n, the

and n being provided w1th cocks Z and n. The reservoirs h and j areconnected to the chamber e by the pipes m and 0, which are provided withcocks m and 0. Fuel may .be I su plied to the reservoirs through thevalve openings h and '1".

The drop of pressure-caused by the, cock (1 causes the liquid fuel to beforced through the spraying nozzle k for combustion in the chamber e.

The pro ortion of fuel to air in e may be increased y decreasing theopening of the cock (1, while the fuller opening of the cock 9 or thepartial closing of the cock 0, will cause a larger stream to passthrough the chamber c. These adjustments. enable the desired temperatureto be obtained.

When the reservoir it becomes empty, it

may be refilled after closing thecooks l and m, the supply of fuel beingmeanwhile obtained from the reservoirj, and the latter can be similarlyfilled after closing the cocks n and 0. The spray may be ignited bymeans of an appropriate electric igniter p.

In Fig. 2 the portion of the pipe 1) between the pipes c and f, Fig. 1,is omitted, the pipe 0 being in a line with and forming a continuationof the pipe I), so that the whole of the air passes through 'the chambere and is led away by the pipe f of Fig. 1, which is now merged in-theoutgoing portion of the pipe I). In this case the requisite head forspraying is caused by the insertion of a perforated plate q in the pipe0, through which the whole of the compressed-air stream passes into thecombustion-chamber c.

When the en ine has made a prearranged number of revo utions, the valvem is opened by hand and liquid'fuel is forced from the reservoir itthrough the nozzle 7c into the chamber 6. Almost immediately the primerp is fired and the spray is thereby ignited. In

0th arrangements the ends of the pipes m and 0, which are connected tothe chamber 6, are preferably at a higher level than the to s of thereservoirs h and i, so that fuel is on y supplied to the chamber 0 whenair is flow ing through-the pipe I).

What I claim is 1.- The combination of an air-sup 1y pipe, a reservoirfor liquid fuel, a com ustionchamber, connections from the pipe to thereservoir and chamber, a connection from the reservoir to the chamber,and means in the connection from the pi e to the chamber for reducingthe pressure 0 the air-supply to the chamber as compared with that ofthe 2. The combination 'of an air.supplypipe, .a'reservoir for liquidfuel, a combustionfor reducing the pressure 0 the'air-supply to thechamber as compared with that to the reservoir.

3. The combination of an air-supply pipe,

a reservoir for liquid .fuel, a combustionchamber, a connection from thepipe to the reservoir, two connections from the pipe to the chamber, avalve m the pipe between these two connections, a connection from thereservoir to the chamber, and means in one of the connections from thepipe to the chamber for reducing the pressure of the air-supply to thechamber as compared with that to the reservo1r.

4. The combination of an air-supply pipe,

a reservoir for liquid fuel, a combustionchamber, a connection from thepipe to the reservoir, two connections from the pipe to the chamber, avalve in the pipe between these two connections, a connection from thereservoir'to the chamber, (the chamber end of this connection being at ahigher level than the top of the reservoir,) and means in one of theconnections from the pi e to the chamber for reducing the pressure 0,the air-supply to the chamber as compared with that to the reservoirWILLIAM HORACE SODEALU. Witnesses:

OSCAR FREY, PERCY FREDERICK ALLAN.

